You might hear your lawyer often refer to opposing counsel in court as “brother” or “sister”. This does not mean they are biologically brothers and sisters. It is polite and customary for lawyers to address fellow members of the bar as brothers or sisters of the bar. It is done out of respect rather than a formal rule.
So the next time you hear your attorney say that, do not think they are doing you a disservice because they’re related to opposing counsel. It’s just being nice.